On the Fringe of Superheroes
by Crumby
Summary: Someone—and they had no information on who—had wanted to celebrate his birthday in an exotic location, more specifically in another universe. Fringe agents from both sides had been mobilized for the occasion, ensuring the safety of all involved. In that order, they were all guests, and naturally, the party wasn't just any birthday party, it was also a costume party.
1. Assemble the Party

**A/N:** _Hey, everyone. Today, we're celebrating the awesomeness that is_ **Frea O'Scanlin**_, which is why I wrote this little story._

_That also means,_ _Frea, that shenanigans are probably ahead, because, well...do I really need a reason? If so, I'm blaming your brain, it can be scary—a side-effect from genius, I believe—so I tried to keep up. Or, maybe I'm just incapable of writing anything serious. Your pick._

_In any case, I enrolled your sidekick,_ **mxpw**_, in this adventure so that he would use his super beta skills. He fantastically did, as always. Thank you, BetaMax! Who better than a superhero to beta this story? Seems quite fitting. Oh, did I forget to mention it? There might be superheroes in this story. Maybe. Sort of. :)_

_I also unsurprisingly need to thank _**JoeltotheD**_. Thanks for your help, Joel._**_  
_**

_Happy birthday, Frea!_

* * *

**Chapter 1: Assemble the Party**

Olivia's black boots squeaked under the hallway's linoleum. She should have waited to put on her jumpsuit; the leather clothing wasn't the most comfortable, though Peter had seemed to appreciate it, at least.

"Come on, it _could_ be fun," he told her, squeezing her hand.

"Sure."

He chuckled. "Walter is going to have a blast."

That, she had to admit, made her smile.

"Walter?" Peter asked, as soon as he and Olivia entered the lab. "Are you ready?"

"Son, come take a look at my suit!"

Peter gave Olivia a childish, excited smile and freed her hand to get down the stairs toward his father's current work station. "It is a fake suit, right?"

Olivia knew he was only half-kidding. They were hoping Walter hadn't added any real superhero features to his costume, but they hadn't had the time to make sure. Looking at the red and gold suit from a distance, Olivia thought that it seemed fairly accurate—and impressive, worryingly so. Her eyes swept the room in search of Astrid as she walked in, and she caught sight of something else.

"Walter, what, um…what happened to Gene?"

"Isn't that obvious? She's The Hulk, of course!"

Astrid walked out of her office. "Hey, guys." Their teammate was wearing a black long-sleeved shirt, black pants, and black boots too, but they were more military-styled than Olivia's. Between Astrid, Peter and her, they were a real party, all wearing black. "I tried to stop him."

That would explain the pool of green paint accumulated around Gene's feet. The cow's body was entirely covered in green. Walter hadn't painted her head, so Gene was wearing a green mask, as well as some kind of ripped pants that covered her back feet—Olivia guessed it was supposed to complete The Hulk outfit.

Peter moved to rummage through a closet. "You're not taking Gene to the party, Walter."

"Is that even safe?" Olivia asked. "The paint?"

"Of course, it's safe!" Walter said. "And we're all going, aren't we?"

Grabbing two plastic bags, Peter said, "Yes. All we humans are going."

"But—"

"No pets. Did you do something to this?" Peter said, taking out his quiver.

"We can take a picture with Gene before leaving," Astrid told Walter. "If we hurry."

"Marvelous idea, Arrow. Go fetch my Instamatic."

"_Or_," Peter said, "the new camera I bought you." At the look Astrid gave him, he went on, "Which _I_'ll go fetch, of course."

"Thank you," Astrid said.

Peter gave Olivia one of the plastic bags on his way. She had her own accessories to add in order to complete her costume, though she wouldn't be covering her blonde hair with a red wig.

"Any word from Lincoln?" Olivia asked.

"Who?" Walter said.

"Agent Lee. Blond with glasses? Plays chess?"

"Oh! Remarkable chess partner."

"He sent us this report," Astrid said, handing Olivia a file, "but it doesn't sound like they've learned anything we didn't already know. You think the attacks will resume? It's been a month."

A month had passed since the last incident, and they still had no clue about who was behind it, or why. Even if no civilians had been hurt so far, the nature and danger of the three incidents were worrying and the unknown surrounding them even worse.

"They probably will." Olivia skimmed the file. "Still no word on who the birthday boy is?"

"Maybe it's a birthday girl," Astrid said.

Olivia tilting her head to the side in agreement. "I'll take that as a no."

"I've got it," Peter said, rejoining the room, and taking off his pea coat. "Come on, everybody in costumes, or we're going to be late!" He put his sleeveless jacket on. "Did you do something to this, too?"

"Only to make it more authentic, son."

"That's what worries me." Peter turned to Olivia, and ran a hand over his chest to smooth his jacket. "How do I look?"

"Well…" Olivia paused, both for effect and also because she was mostly just ogling her boyfriend. "Clint, I think I'm starting to like our choice of costumes."

Peter's smile reached his eyes in a gleam. "Me too."

—A—

Peter turned in the passenger seat as Olivia pulled over. "You and I will wait in the car, Walter."

"Why?"

"You're not wearing pants."

"I know I'm not wearing pants, Peter, but I can put my suit back on."

"I can stay with Walter," Astrid said. Olivia saw Astrid's jerk of the head in the direction of the DVD player emplaced behind Peter's seat in the rearview mirror. "And we can finish our Sponge Bob episode."

"You sure?"

"Mhm."

"Okay, well, shall we?" Peter told Olivia.

Since The Bridge facility was more secure than even the Helicarrier probably would be if it actually existed, it was for the best that Olivia and Peter didn't have to explain why Iron Man was with them, especially if Walter had added a surprise or two to his suit, which they still hadn't ascertained. They expected Lincoln, but Agent Broyles was the one waiting for them. Both of them came to a halt upon seeing him, and it took all Olivia had not to let out the smile—or more—tugging at her lips.

Broyles was wearing Captain America's Stars and Stripes uniform in all its glory: The blue tights, the red gauntlets and boots, the belt, he was missing the mask and shield, but it was enough of an image. As disturbing as it was to think about her boss in that way, he didn't look bad in it either.

Olivia thought that her boss muttered something about Nick Fury, but she couldn't be sure, and he greeted them when they finally approached.

"Sir," Olivia said.

"Agent Lee should be here any minute," Broyles said. "Have you read his report?"

"On the way," Peter said. "Walter might have a theory. We want to make some tests tomorrow."

Broyles pursed his lips. "Keep me informed."

The door behind Broyles opened, giving view to Lincoln. "Hey, guys." He sounded a little out of breath. Olivia watched as he took in Broyles' appearance, made his cape twirl as he turned to Peter in his sleeveless jacket, and her with her coat open, letting her jumpsuit and Black Widow belt buckle show. "Aww, nobody told me you were all going as Avengers. You just said superheroes!"

"Two guys in tights _is_ kind of awkward," Peter said, looking at Captain America, before switching back to Lincoln. "How do you like it over there in the DC universe, Kent?"

Olivia suppressed another smile. Had nobody given Lincoln any details about their costumes at all? Olivia hadn't, but she thought someone would have. Oh, well. He _had_ always struck her as a Clark Kent type anyway. His Superman suit fit.

"ETA on the party?" Broyles asked.

They literally were waiting for party goers coming from the other universe. Someone—and they had no information on who, not even Broyles—had wanted to celebrate his birthday in an exotic location, more specifically in another universe. It must have been a very important personality, high on the governmental hierarchy, for it to actually be happening. Fringe agents from both sides had been mobilized for the occasion, ensuring the safety of all involved. In that order, they were all guests, and naturally, the party wasn't just any birthday party, it was also a costume party.

"Five minutes," Lincoln said.

—A—

Olivia sipped on one of the fancy cocktail that the waiters had been serving. "I still can't believe this is actually happening."

"At least they said no about Greece," Peter said.

The birthday…_person_ had requested to go to Greece, of all things, at first. Apparently, the Acropolis wasn't as well-preserved on the other side. Fortunately, it had been decided that they would have to stay in New York City if the party was to happen.

"It is kind of ridiculous," Agent Dunham said. "Though, they did keep information pretty tight. _We_ don't even know who it is either."

Joining the three of them, Captain Lee extended a glass of water to his colleague, before glancing at Olivia. "Doesn't White Widow have red hair?" Three pairs of eyes shot him a look. "Right," he chewed on his lower lip, "awkward."

Peter questioningly mouthed, "White Widow," to Olivia, which she replied to with a brief shrug, though she couldn't help but smile at his obvious disapproval. He shook his head, and broke the silence. "So, Luke Skywalker and Mara Jade," he said. "That's an interesting choice."

Olivia had recognized Captain Lee's costume, but not her counterpart's. Her Star Wars knowledge stopped at the movies—or rather, her universe's movies. She had opted to give the Bishops a father-son movie night when they had planned on watching the sequels.

"They were badass in _Episode IX_," Lee said, "you've got to admit."

"I know!" Peter said. "Thanks again for that by the way. Walter loved them. The sequels are so much better than our prequels."

"No worries. Where's Mantis?" Captain Lee asked Agent Dunham.

"Grabbing drinks with Superman. Which, by the way, is also an interesting costume. For all sorts of reasons." She gave Captain Lee a look over, and grinned.

Unlike Olivia, her redheaded counterpart apparently didn't have any problem thinking of her boss in that way. Although, Captain Lee appeared like a confident guy, and even a little arrogant, at times, Agent Dunham's comment still reddened his cheeks slightly, and Olivia had to hide her smile behind her glass.

Peter cleared his throat. "Who's Mantis?"

Olivia had heard someone calling their Charlie this, on their way into the building where the party was being held. "Agent Francis," she said.

"Oh, right. The insect guy. I'm sorry, but can I?"

Captain Lee frowned in confusion, visibly not following what Peter was pointing at. Agent Dunham chuckled and unfastened her own lightsaber, before handing it out to Peter, who asked whether it was safe or not. She assured him it was, and the hum of the fake-weapon was rather well-done, Olivia thought, when Peter switched it on and started moving around.

"Shouldn't Agent Francis be Spider-Man?" Peter asked, between motions. "You know, with his…condition."

"Spider-Man?"

"You don't have Spider-Man?"

"Uh-uh."

"Aww, that sucks."

"Charlie's girlfriend is a bug girl," the other Olivia said. "Probably why he's Mantis. I think, in his case, the real party will start when he'll get back home."

Peter's laugh transformed into a choke when Olivia elbowed him and discreetly indicated him in Nina Sharp's direction. Not only was Nina talking with Broyles, who had now put on his Captain America mask and was holding his shield, which was enough to make any Fringe agent choke tonight, but Nina was wearing her own outstanding costume. A red cape was draped around her shoulder, above her grey armor. The gauntlets seemed a little shinier than necessary; it seemed that some diamonds had been added. And the hammer in Nina's hand was imposing.

Maybe sensing the attention, the woman turned her blonde-wigged head toward their little group and lifted her cocktail in greetings. Olivia and Peter returned the gesture.

"I guess we're only missing a Loki, now," Olivia said.

"Oh, we have one." Peter looked around the room. "Our Scotland Yard liaison, the one who's got a twin."

"Agent Simon?"

"Yeah." He lowered his voice. "I think his sister is a spy or something, he's very evasive on the matter." Olivia's skepticism must have showed, because Peter dropped the subject, and looked around again. "I can't find him now. You can't miss him, though, he's got the gold Viking helmet and everything. Oh-uh, Walter's at the buffet."

"I guess that's our cue," Olivia said, before she and Peter excused themselves. Passing one of the numerous yellow and blue costumes of the party, Olivia spun back around after a few steps. "I meant to ask," she told the other Dunham and Lee. "What's with all the minions?"

—A—

"Maybe you should have been Iron Man," Walter said to Nina in a tone of confidence, "you already have the arm."

"Walter!" Astrid said.

"It's okay," Nina said. "He isn't wrong. Though, I can't fly yet."

"With the suit, you could," Walter said.

"But _you_ can't, right, Walter?"

"No, son, I couldn't add the flying features on such short notice."

They had received the "party invitation" the previous weekend. Walter had been watching _Iron Man 2_ at the time, hence their costumes.

Olivia shared a worried look with Astrid and Peter. She would have thought that Astrid's eye patch—she had completed her costume once they left the lab, and was also wearing Nick Fury's black leather coat—would have made it difficult, but her colleague's expressions were clear.

"Your Thor impersonation is excellent. May I?" Walter pointed at Nina's hammer. The swooshing sounds of the Iron Man suit were still a little unsettling.

It had taken them all by surprise at the lab earlier, when Walter had put on the suit to pose for the picture with Gene. He had powered up the suit, and…it'd moved. Now, Walter wasn't wearing the helmet because it clashed with Walter's appreciation of the buffet, which took some of the effect of the suit away, but anyone that knew Walter would still be on their guard about the rest of the costume.

Olivia scanned the room. There hadn't been any incidents with the trip from the other universe, no journalists to ask questions, no birthday person to recognize either, for that matter. She was starting to wonder if the party really was a birthday celebration. Her eyes stopped on Agent Valley walking stiffly toward Broyles across the room. He whispered something to him, and his eyes traveled among the attendance, concerned, until he spotted his group of Avengers.

Olivia separated herself from the crowd with a few steps as her boss approached. "Sir?"

"We have a situation," Broyles said. "There's been another breach." He didn't waste time giving her more details and asked Olivia to bring her team to a conference room in the building for a briefing, before hurrying in the direction Agent Valley had left.

Following the news, Peter looked at Astrid. "You should say it, Fury," he said. Astrid's brow furrowed as Walter smiled at his son, his eyes sparkling. At Astrid's silence, Peter went on, "Fringe Division, assemble."


	2. A Monster of a Party

**A/N:** _It's baaack! Thank you all for reading and reviewing._

_The fabulous_ **mxpw**_ worked once again his beta magic on this chapter. Thank you, Maximus. __Thanks also to _**Joel**_ and _**Lin**_ for the support and help._

_Finally, thanks _**Frea**_ for inspiring this story. I'm not sure how much fun it's going to be for you, but it's been quite the adventure on my part. ;-)_

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**Chapter 2: A Monster of a Party**

"I guess The Hulk decided to join the party," Lincoln said, after he'd stepped through the threshold, probably catching sight of the video on the monitor across the conference room. Captain Lee and Agents Dunham and Francis followed through.

Seeing as the Fringe case that had kept them busy the previous month was affecting both worlds, the two Fringe teams had decided to join forces. Lincoln had actually just spent the last couple of days Over There to work with Captain Lee's team on the case that they had all come to call "The Hulks Case" after the third incident.

A month ago in New York, Sarah Walker and Zondra Rizzo from the CAT Squad—the CAT Squad! Olivia still couldn't believe they had met the pop girl band—had been taken to the alternate universe via a breach, and chased down by a creature almost similar to the one currently on screen. Sarah had compared the monster to The Hulk afterwards, and although Agent Dunham and Olivia had laughed at the time, the moniker had stuck.

None of the three creatures the two Fringe Divisions had had to deal with—four now, with the one on screen—had been green, they were, in fact, relatively human skin colored, if a bit grey. But they were all hyper-muscular, and giant human-sized, of sorts.

So, Hulks.

The creature on the video smashed its fist through a wall, leading Olivia to say, "I don't see how that's a party."

"We already have a Hulk," Walter said, his tone one of disapproval. "Gene's The Hulk."

"And," Agent Dunham added, "it's not a costume."

"Uh…" Lincoln said. "Sorry?"

The video froze, and Agent Valley, who was the only one sitting at the conference table, spoke without looking up from typing on his laptop. "There's more."

"Another?" Captain Lee said, as a second creature appeared on screen. It resembled the first one they had just observed; only its figure was slightly slenderer, making its movements more agile.

Two creatures simultaneously during the same incident: this was new.

"How many are there?" Olivia asked.

"As of right now," Valley replied, "we've only spotted two."

"I don't think my people would have waited this long to contact us if that was the case," Captain Lee said, "but we better report, and make sure that there aren't others running around on our side as well."

Agent Broyles nodded. "I agree."

"What about the breach?" Agent Dunham asked. "Any damage?"

"Nothing apparent on this side so far," Broyles said.

"Mind if one of us sticks around as part of our cooperation?" Captain Lee asked. "We might as well take the opportunity to maybe learn something."

"As long as we're clear on whose orders they follow," Broyles said.

Turning to Agents Dunham and Francis, Captain Lee said, "Decide."

Olivia saw her boss' eyebrows raise just a tad—probably a reaction to Captain Lee's management ways. Then his eyebrows definitely rose when Agent Dunham proposed rock-paper-scissors to determine who'd stay.

"Uh-uh," Agent Francis said, grinning. "It's my turn. You owe me one for the lizard case."

"Oh, fine." Agent Dunham turned to Captain Lee. "Shall we, Luke?"

They departed, and as the door closed behind them, Olivia asked, "Where are the Hulks now?"

"As far as we can tell, the two of them are inside that building." Valley jerked his head at the screen. The agent had frozen the image on one of the creatures getting through a wall it'd pierced through.

"Chopper's waiting for you on the roof," Broyles said.

Olivia's hand immediately moved to her thigh holster, in order to check on her gun. Her costume had actually allowed her to be armed, which had been one of the few characteristics of the outfit that she had had no problem with. Like Olivia, the other agents didn't waste time. Agent Francis placed his insect mask on the table, as Lincoln tugged on his red cape to take it off.

"Where to?" Peter asked, moving his quiver over his head.

"Maybe you should keep it, son," Walter said.

"Why?"

"It could come in handy," Walter said, with an excited smile that only suggested of trouble to Olivia. "I added a few features." He walked to Olivia and reached for her left wrist, fingering the cuffs around it.

The device was not all decorative, Olivia realized, as it lighted blue and made a sound of charging batteries under Walter's ministrations, just like Black Widow's wristcuffs had done in the movie. "You can tase the creatures with this."

"Walter!"

"I know!" he said. "Thrilling, isn't it?"

—A—

Olivia felt her feet leave the ground slowly. Air became scarce as the Hulk's hand tightened around her throat. She felt the cold of the glass door behind her, contrasting on the nape of her neck with the heat of its hand. Her boots strummed on the cement, desperately trying to find hold and release the pressure. The creature only clenched more.

Its eyes weren't as devoid of anything but raw anger as the ones of the monster she had faced the previous month. Something—and Olivia couldn't figure what—was different, but its gaze was bestial nonetheless.

The autopsies had showed that the Hulks had once been human beings before transforming. Unlike Bruce Banner, though, there was no turning back, no switching on and off. Once these people had changed, they were monsters for good, the process resembling more what Steve Rogers had been subjected to by Dr. Erskine.

The Fringe team hadn't had the opportunity to try and reason with the first Hulk during the first Chicago incident, since the creature hadn't survived more than half an hour by Walter's estimation. It had been found dead before it could endanger anybody. However, Captain Lee's team had tried to stop the second Hulk without killing it during the second incident Over There in Missouri, but they'd been unsuccessful, forcing them to use lethal weapons. Olivia hadn't tried the third time in New York, because two civilian lives had been at risks. The only way to stop the monsters was to either kill them, or try to restrain them somehow. A how that Olivia hadn't had with her at the time and couldn't have waited for, so she hadn't hesitated.

But because the monsters had been human, and even though there wasn't an off button, there might still be a chance that, with enough time, Walter could reverse the process. So tonight, they had brought tranquilizers.

The monster currently attempting to strangle Olivia had been shot with the equivalent of what would put an elephant to sleep, and the monster was still going. Olivia tried to push it with her hands. It was futile, she knew, even as her vision clouded—

"Olivia!" she heard.

Peter was calling her.

Though she hadn't known she'd closed them, Olivia's eyes re-opened at the realization. Peter had been trying to stop the other Hulk in the warehouse with Agent Rand. Maybe Peter needed her help. Maybe he just needed her to hold on a little bit longer, so he could make the creature loosen its grip. In front of her, Olivia's gaze landed on her right hand as her fingers scraped the creature's shoulder. Then she remembered Walter's words.

Mustering her forces and will to catch the monster behind the head, Olivia didn't have the energy to care now, but she knew she'd regret this later. She activated her wristcuff with a finger. The taser immediately immobilized the Hulk—and sent a pulsating charge through Olivia's body.

It only lasted a brief moment, as Olivia's finger cramped and she let go of the taser.

The Hulk's hand unclenched.

Olivia could breathe again.

_Thrilling_, she thought, before reaching out once more. She kept the taser on, watching the Hulk's knees slowly giving out, while she herself tried to get a hold of her breathing and relax her contracted muscles. When she was convinced it was weakened enough, she threw a punch at the creature's face—it hurt like an explosive crush—and grabbed its neck, pushing down and to the side. Pivoting on right foot quickly, she threw him toward the ground. She hadn't anticipated it, but the creature's head crashed into the door. The glass broke into a million pieces. Blue blood erupted from several cuts, and the creature fell to the floor across the debris.

Cognitive recalibration wouldn't work on this Hulk, unfortunately.

Indeed, the creature shook its head, in a gesture that looked more animal than human—it was still moving. Olivia wouldn't have much time.

Unless, she realized, seeing a piece of glass that hadn't fallen yet hanging above the Hulk, it got guillotined.

The piece of glass was unlikely to fall on its neck, and even then, Olivia wasn't sure it would be a fatal blow. But in any case, she didn't wish that fate for anybody—or anything. She couldn't forget they'd been human once.

So, reluctantly, she grabbed her back-up gun—the first one had escaped her during the fight. The monster tried to get up. She put a bullet through its head.

After the third incident in New York, and the multiple magazines it had taken Olivia to put down the creature, Walter had said it was the easiest way to stop them. Clean bullet to the temple. Though several bullets might actually be necessary, it would be more efficient than targeting the rest of the body.

Olivia fired a second time, to be sure, and spun around looking for Peter. Trying to call his name, she was suddenly reminded of the stranglehold she'd suffered only minutes ago, and coughed roughly. She tried again.

"Peter?"

Right when her eyes found his across the hall, gunshots rang. Olivia's heart skipped a beat. Blue blood spattered on Peter's face, before the creature standing right in front of him collapsed.

Agent Ballerman, the team's sniper, had switched his tranqs for real bullets.

"Yuck," Peter said, and wiped his mouth with the back of his hand. "This is disgusting. Not that it's a surprise."

"Are you okay?" Olivia asked.

"Yes. You? What—your neck!"

"I'm fine." It hurt, the skin burned, she wasn't sure whether the twitching was real or just an impression, but she'd live. Olivia kneeled down next to Agent Rand who'd been thrown against a shelf during the fight. "Rand? How are you feeling?"

The Fringe agent blinked, and ran a hand over his face, grimacing the whole time. "I'm okay, I think."

Olivia activated her comm. "Astrid? We need a medical team."

"They're on their way," Astrid said. "ETA..."

"Three minutes," Agent Valley said.

Both of them had stayed in Manhattan with Agent Broyles and Walter, where the party was still going unperturbed.

"Can you stay here by yourself?" Olivia asked Rand. He nodded, if weakly. "Lincoln?"

During the helicopter ride to Queens, where the Hulks had showed up, Astrid and Valley had spotted a third creature, a block away from the first two. They had decided to split up. Lincoln and Agent Francis had gone after the isolated Hulk, while Olivia, Peter, and Agents Ballerman and Rand had gone after the duo.

"He got knocked out," Francis's voice chimed in. It was strained and breathy. "Tranqs aren't working."

"Didn't work for us either," Olivia said. "We had to put them down. Is Lincoln hurt?"

"I'm not sure," Francis said.

"I'm coordinating with the medics," Astrid said.

"There's more of them. We spotted at least two here, and another was—"

"Francis?" Olivia asked.

After a few seconds, that Olivia used to look for her lost gun, he resumed speaking. "Got one. There's one left here, but I don't think I can take him while covering for Lee. Plus another Hulk is heading your way."

"Ballerman?"

"On it," the sniper said. "I'm heading to the roof."

Olivia looked at Peter, who'd been examining the bodies. He had his phone in hand and seemed to be taking pictures or filming. "Anything?"

"I'm sending over a few pictures to Walter," Peter said. "What on Earth is going on?"

That was a good question. The Hulks were multiplying, and if one of them had looked like the one Olivia had killed a month ago at the CAT Squad concert, she could tell there was still something different about it, and the second one definitely looked different.

The three Hulks from the first three incidents hadn't been identical either. It was unclear how much of it came from the original physique of the people transforming, but there was definitely something at play here.

The experimentations were _on_.

Since she didn't have much to reply to Peter, Olivia focused on what was next. "We need to catch up with Francis." Peter buried his phone back in his pocket and nodded. Switching to the comm, Olivia said, "Peter and I are on our way." After one last glance exchanged with Rand to make sure he'd be alright, they took off running.

It would be a long night, Olivia could already tell.


	3. Life of the Party

**A/N:** _You've guessed it if you've read _Requiem for Stuck Pop Stars_, the Fringe incident with the CAT Squad mentioned in the previous chapter is what happened in this Chuck/Fringe crossover. The two stories can be read individually, though, there's no previous knowledge needed._

_Thanks for reading and reviewing. Thanks to _**JoeltotheD**_ for beta reading this chapter for me. All remaining mistakes are mine. Enjoy!_

* * *

**Chapter 3: Life of the Party**

"Lincoln's fine," Peter said, coming back from the ambulance.

Their partner was sitting on the back of the medical vehicle. He had put on a pair of black pants and a black FBI t-shirt on top of his Superman costume before jumping in the chopper, leaving his long blue sleeves apparent underneath. The right one was ripped, but along with the thing he was pressing to his forehead—likely an ice pack—it was the only sign of his misadventure. He seemed okay.

"What now?" Agent Francis asked.

Olivia brought a hand to the nape of her neck as she tried to stretch. The tasering hadn't been full load, but it did leave her slightly stiff. "We need to find where they're coming from," she said.

While regrouping with Francis and an unconscious Lincoln, Peter and Olivia had taken out another Hulk without too much difficulty, thanks to spotting it in time to allow Olivia to shoot it efficiently. While that one hadn't been as muscular, it had seemed more intelligent, which was worrisome.

On his end, Agent Ballerman had climbed up to the roof of the building where they'd left Agent Rand to see a medical team. From his position, Ballerman had not only been able to snipe the Hulk that Francis had alerted them about, but he had also caught sight of a couple of other monsters.

Now, the new creatures had been taken care of, Rand was back to his feet, Lincoln was recovering, and another team of agents had arrived to retrieve the bodies.

"Olivia?"

Bringing her hand to her ear, Olivia activated her comm. "Yes, Astrid?"

"Captain Lee had Agent Farnsworth sent us the precise location of the breach," Astrid said. "They didn't have any creatures on their side, but Agent Farnsworth Over There has been observing breaches closing and opening every ten minutes or so. First breach was seventy eight minutes ago. I'm sending you the coordinates."

"Walter, any theories?" Olivia asked, as she looked over the GPS on her phone.

"Oh, uh, yes," Walter said. "So far the breaches have always happened on soft spots that the machine hasn't healed yet. It's the case here as well. I believe whoever is creating these Hulks is using soft spots because the laws of physics are disturbed at these locations."

"Why a breach, though, Walter?" Peter said. "Why do they need to link the two universes that way?"

"We've tried to explain it as a cause for the apparition of the creatures," Walter said, "but it might merely be a consequence."

Olivia frowned.

"A side-effect from the transformation process?" Peter asked.

"Perhaps, yes."

"Okay," Olivia said. The location of the breach was only two blocks away. "Let's found out."

—A—

The GPS coordinates led them to an office building. On the first floor, some lights were still on, but it seemed as though the work day was over. The night watch assured them it was and that the building was deserted, but considering Hulks running around might have passed unnoticed by them, Olivia wouldn't be taking any chances. She hoped none of the employees had decided to do some extra work during the night; dealing with the creatures would already be enough excitement, no need to add civilians to the mix.

Agent Francis, Peter, Olivia, and one of the guards made it to the breach location without trouble. It was an empty waiting room. Nothing was out of the ordinary.

"It could be on any of the other floors above us," Peter said, looking over at the ceiling. "The coordinates would be the same."

"Quite right," Walter said over the comm. He and Astrid were following the team movements thanks to cameras the three agents had hung to their collars.

"What exactly are you looking for?" the guard asked.

"You don't want to know," Peter said. "How many stories is this building?"

"Eight."

"We're gonna have to check them all," Olivia told the guard.

He nodded. "I'll lead you to the elevators."

They started walking, and after a moment, Francis asked, "Should we split up?"

"I don't know about you, but if there are other…" Olivia stopped herself when the guard looked at her over his shoulder, "…guests, I'd rather not be alone when I find them."

"Good point."

The guard seemed perplexed, and slightly alarmed, which told Olivia he wasn't one hundred percent sure that nobody was in that building.

"Here you go," he said, and called the elevator. Nothing happened. He pushed the button again.

"You've got to be kidding me," Peter said.

"I don't understand," the guard said, trying all the elevators. "It was working fine earlier."

"Can't be a coincidence," Francis said. "Definitely not splitting, then. Don't want to end up like Lee."

"That bad?" Peter asked.

"I always thought Mantis could take Superman in a fight, but these guys can probably take Mantis, Superman, and three of their cousins."

It didn't do anything to reassure the guard.

"We're going to take the stairs," Olivia told him. "Call one of your colleagues to join you at the building entrance. You stay there, and wait for our team. We'll send someone to have a look at the elevator. If you see anything, don't play hero. Stay out of harm, and call us."

"We've had to deal with robbers before," he said, though Olivia thought his complexion had lost some colors.

"Call us."

Putting a hand on his back to lead him away, Peter said, "Trust me, it wouldn't be worth the payroll."

"Astrid?" Olivia asked.

"Heard you," Astrid said. "Sending a team as we speak."

The three agents started up the stairs. Carefully silent, flashlights and weapons raised, they didn't waste time in the staircase. Thanks to large windows, the second floor was fairly well lighted despite the gloom of the night. A shop sign across the street, blinking red, was coloring part of the room. It revealed office cubicles. Dull, never-ending office cubicles.

Walking among them, Olivia put away her flashlight in search of her phone, and felt Peter's arms blocking her way. He was tense, and had a finger raised over his mouth when she looked up. He nodded to her three o'clock. The Hulk was turning back in their direction as she caught sight of it. They jumped, both on either side of the alley. Ducked behind a cubicle, Olivia looked to her left to check on Peter and Francis. The other agent had followed and was crouched next to Peter.

"Can you shoot it from here?" Peter asked Olivia, whispering.

She was trying to assess that exact question. "I can't see it from that angle."

"Use your crossbow, son," Walter said over the comm.

"This isn't really the time, Walter," Peter said.

"Do it. It'll work."

Peter glanced over at her, and Olivia gave him a light shrug. She didn't even know if he knew archery, let alone if he was any good at it. But if it didn't work, she'd move and find a way to shoot the creature. Peter unfolded the bow.

"You serious?" Francis said. "It looks like you bought this toy at Target."

"I did," Peter said, and she could hear his smile. "I thought that was appropriate."

"Push the button three times in quick succession, Peter, it'll give you the right arrow."

"You and I will need to have another talk about our costumes when we come back, Walter," Peter said even as he seemed to be following his father's instructions.

"Aim at the chest," Walter said. "That should do it."

Peter took aim. As soon as he released the bowstring, Olivia heard an electronic beep. The arrow pierced through the creature's front, which made it bark, loudly. So much for discretion and not alerting of their presence whoever else might be in the building. The cry only lasted a handful of seconds, however, because even as Olivia rose to her feet to approach the Hulk and finish it, there was another, longer beep.

Then, an explosion.

Olivia lifted her hand in front of her to protect her face.

Tearing a hole through the creature's chest, the arrow exploded, seemingly killing the monster on the spot.

"Holy crap," Olivia heard Francis say behind her. They needed to act fast if they didn't want whoever might be here to flee.

"You were right," Peter said, likely addressing Walter, "it worked."

With one eye on her phone to follow the GPS signal, Olivia led the way. She tried not to think too much about all the questions she had, and stay focused on the situation at hand, but she couldn't help wonder what exactly they—whoever it was—were trying to accomplish.

The team assumed that the Hulks weren't all similar because the men behind the curtains were changing the parameters of the transformation. But why so many times on the same day—today—after three single attempts a month ago? And what was the purpose of these Hulks?

Granted, mad scientists didn't always make the most sense, but one could hope.

A sound, like the slam of a door, resonated inside the office building, interrupting her musings. All three agents spun around in the direction of the noise.

"They're getting away," Peter said.

"Or it's another Hulk," Francis replied.

"We can't risk losing them," Olivia told them. "Peter and I will go after it. You go to the breach." More people on the one moving target made sense.

"Roger that," Francis said, and fished out his phone.

Olivia and Peter ran off. They passed a hallway, before there was more noise, guiding them to another room, still full of cubicles.

"There," Olivia said, pointing at the flash of golden clothing she'd seen, before shouting, "Freeze, FBI!"

The man, just like bad guys always seem to, didn't stop. He had the advantage of knowing where he was going, but Olivia was a highly trained FBI agent in shape, and after a minute, she was gaining terrain on him. Peter took a left behind her, and fired a few gunshots to slow their quarry down. The man ducked, and the damn office cubicles were perfect hiding. So much so, that he disappeared from view.

"Where the hell did he go?" Peter said, voice low.

Olivia stopped her run, carefully approaching the corner they had last seen him. She stepped in, weapons at the ready, but the alley was empty. Hearing a creaking noise, she moved just in time out of the way of the cubicle ahead, before it could collapse backwards on her.

The man reappeared from nowhere in the confusion, and took off once more, flinging whatever objects he found behind him to slow them down. _What a cliché_, Olivia thought, they weren't even behind him. Peter immediately climbed with two long strides on the cubicle debris that Olivia had just avoided, his eyes searching around the room.

Right, if the man wanted to escape, he'd have to find an exit.

Peter pointed about thirty-five degrees to the right, and Olivia nodded, before starting in that direction, while Peter jumped down and rushed after the man.

The intensity of the pursuit was beginning to show in her breathing. Olivia could feel sweat on her face and against the collar of her leather jumpsuit. But she kept going, lowering herself to stay unseen. Peter, on the opposite, was making a show, shooting bullets on the man's way.

It happened all very quickly. The man stumbled, and as a lot of people had the reflexes to, he looked behind him to check Peter's position. He didn't see Olivia arrive from the side as he headed to the door. She lurched forward, tackling him down. The man tried to wrestle, but Olivia straightened up first, and threw a punch for good measure.

"Freeze," Peter said, as he arrived next to them, pointing his gun on the man.

This time, he stopped.

A good thing too, because Olivia was busy frowning, as she took on his appearance. "Agent Simon?" The golden and black clothing was part of his costume, Olivia realized. Was their Scotland Yard liaison the man responsible for the Hulks case?

"It figures," Peter said, panting, "that Loki would be behind this."


	4. Party Crashers

**A/N:** _Thanks to _**LinShoe85 **_for beta reading this chapter, and thanks to all that have read and reviewed. Here's the penultimate chapter of this story._

* * *

**Chapter 4: Party Crashers**

Without care, Peter shoved down Agent Simon into a chair, making the Englishman hiss. Olivia had cuffed his hands behind his back, but she handed Peter a bunch of wires she'd snatched from a computer, so he'd tie the man to the furniture as well. Better safe, than sorry.

"So, Agent Simon." Olivia positioned herself in front of him, purposely pausing. "What are you doing here?"

After checking with Agent Broyles, it was decided that Peter and Olivia would start interrogating Agent Simon to look for some answers. Indeed, Agent Francis hadn't made it to the breach location. The second floor had been clear. And then, Francis had been blocked on his way, stumbling upon several locked doors. He had been trying to either get around it or find a way to unlock the way, both taking some time. He'd since been joined by Lincoln—once Peter and Olivia's partner had been released by the medical team—and a few other agents. They were working on it, currently on the fourth floor. But the team needed answers now.

Simon didn't reply, and after a moment of silence, he cursed and sent a glare Peter's way. Peter glared back, tugging even more forcefully on the power cord he was tying around Simon's torso.

"Who are the people that you're changing into..."

"Hulks?" Simon offered in his British accent at Olivia's hesitation. He smirked.

"Yes, Hulks," Olivia said, dryly. The man had been onto them the whole time, pretending to be on their side. It stung. "Who are they?"

Simon just looked away, ignoring her.

"She asked you a question," Peter said, shaking him, before crouching down to tie his legs.

Simon's breathing was labored against his restraints as he straightened up. "They're volunteers," he said finally.

"Volunteers?" Olivia asked.

"Yes."

"And now they can't confirm their volunteering, can they?" Olivia said.

Simon looked away, over Olivia's right shoulder. "They knew death was a risk," he said. Even though his words could have suggested otherwise, he didn't sound like their fates had meant nothing to him. "We didn't mean to hurt anyone, and we _didn't_—no civilians were hurt."

"What about Rizzo and Walker?" If it hadn't been for Olivia, the two pop stars might have been killed on the third incident last month.

"It was an accident," Simon said, glancing back at her. "They weren't supposed to be there, they shouldn't have been taken to the other side where Bryan was."

Bryan—so that was the name of the person Olivia had had to kill. She considered Simon's words as Peter rose to his feet and settled beside her, arms folded over his chest. Every incident had happened in deserted areas, that was true, and Simon couldn't have easily anticipated the civilians' involvement. Though, tonight, the Hulks were dangerously wandering around. Even if the individuals transforming—such as Bryan, if Bryan even existed—were volunteers, the whole affair was hardly innocent. It was even less secure.

"Who's 'we'?" Olivia said.

"What?"

"You said 'we'."

"Oh, uh, the volunteers and I," Simon said.

He didn't seem so sure about is own answer, which send warning bells to Olivia's head. It reinforced the possibility that he wasn't working alone. Not that it was in any way surprising.

"What are they volunteering for, Agent Simon?" she asked.

He rolled his eyes. "My name's not Simon."

"No? What is it, then?"

"Doesn't matter."

"Then we'll keep calling you Simon," Peter said. "I like it."

The man glowered at Peter once more, before sighing. "Dr. Clarkson."

"What are your associates volunteering for, Dr. Clarkson?" Olivia asked.

"Saving the world."

Peter snorted. "What on Earth are a bunch of Hulks going to save the world from? And don't say Chitauri!"

"Your father was right, you know," Simon told him.

"Let me guess," Peter said, "you're a big fan of his work."

"Aren't you?"

Olivia spoke before Peter could reply. Exploring Peter's daddy issues wouldn't exactly help. "What was Dr. Bishop right about?"

"We need to prepare ourselves."

"Okay," Olivia said, and waited for Clarkson to focus back on her. "Prepare ourselves how? What for?"

"The Cortexophin trials were Dr. Bishop's attempts at creating super-soldiers." An all too familiar, uneasy sensation passed through Olivia's stomach. "This," Clarkson said with a bob of his head. "This is mine."

"Great," Peter said. "Another Dr. Frankenstein."

Olivia was more tempted to call him a Dr. Erskine-wannabe, considering how this case was seriously becoming more and more Hulkian by the second. "Why do you need super-soldiers?" she asked.

"We need to prepare ourselves."

"You said that already," Peter said.

Clarkson's eyes locked on Olivia's with such intensity, she doubted that he didn't truly believe what he was saying. "They're coming," he said.

Olivia broke the stare when she felt her phone buzz in her pocket. Their comm had been turned off after separating with Francis.

"Agent Dunham," Agent Broyles said, before asking about the interrogation. After sharing a look with Peter, she was assured he would stand guard. Olivia took a few steps away, turning her back for more privacy.

She told Broyles what Clarkson had told her and Peter, and learned that the fourth floor was clear. Lincoln, Francis, and their team were presently trying to get to the fifth.

She was still hearing Clarkson talking to Peter at the same time. "They're coming," he said again. "A _war_ is coming." She whirled around in their prisoner's direction, still on the phone, when Clarkson added, "And you're too late."

"Son of a gun!" Broyles said.

"Peter," Olivia said with alarm, before turning on the speakerphone as he joined her. "What is it?" she asked into the phone.

"Agent Lee's team has encountered another creature," Broyles said.

"Anybody hurt?"

"No," Broyles said, "but this one is smarter. I'm sending Agent Rand to retrieve Dr. Clarkson. As soon as he gets there, regroup with Agent Lee."

Olivia's reply died on her lips when a roar—a sound she recognized from previous Hulks—rumbled through the office building.

In the same way he'd done while pursuing Clarkson, Peter jumped on a desk inside a cubicle, and twisted his neck around, his eyes searching for the source of the roar, she assumed. Olivia had a fleeting thought about Peter sort of taking this Hawkeye's thing to heart, before he spoke. "I see it."

"Agent Dunham?" Broyles asked.

"Sir," Olivia said, "we have another Hulk on our hands too."

"I'll wait for Randy and stay with Clarkson," Peter said. "Go."

Olivia glanced at their prisoner, remembering his words about being too late. "Someone else is still changing people into Hulks," she said. "We need to get to the breach."

"Actually," Astrid's voice chimed in, "José and I have an idea."

"José?"

"Agent Valley," Astrid said. "He's looking into it."

"Okay," Olivia said. "Peter's staying with Clarkson. He'll call you back."

"Good luck."

Olivia put away her phone, and turned to Clarkson. "Who's working with you?"

"I told you: the volunteers."

"I think the Hulk's getting out," Peter said, still standing on the desk.

Checking her gun's clip, Olivia asked, "Is there an antidote?"

"What?" Clarkson asked.

"The super-soldier process," she said. "Can it be reversed?"

Realizing what Olivia was asking, something flashed through the doctor's eyes before he looked down. Perhaps it was guilt, because his voice was low when he replied to the negative.

—A—

Olivia hadn't heard any more roaring sounds for a good minute now, and she wasn't sure where she was going anymore. Looking around her, everything in this office building looked the same.

She heard a whooshing sound through the air, before an arrow pierced through a panel ahead of her on the right. She turned back, and though she could see Peter's figure, she couldn't make out if he was telling her anything. Coming closer to the arrow, she understood: It indicated the hallway she needed to take.

Spotting the open exit door the Hulk must have taken, Olivia hurried. She raced down an emergency metallic staircase and ended up in an alley behind the building. Cool air rushed to her skin, making Olivia shiver. A commotion down the street grabbed her attention. It was followed by intense howling—no doubt coming from the Hulk by the nature of the sound. She saw a dumpster fly, plus something illuminating the night behind it. Making her approach slowly with her gun drawn, Olivia's eyes bugged out when she identified the creature on the other side of the dumpsters.

The monster was _on fire_.

What the hell had happened now?

The Hulk kneeled down, and completely collapsed, still burning.

Olivia pushed onward. Not far away, she caught sight of a tall man, dark haired, wearing a duster coat, and handling some sort a stick. He was standing facing the monster, with a bright blue-haired young woman behind him. They both looked up in Olivia's direction when the howling stopped, probably hearing her approaching.

"FBI!" Olivia said. Saved from one of the woman's palm that she placed apparent on the older man's shoulder, they raised their empty hands in front of them diligently. He said something, and even though Olivia couldn't hear the words, she recognized him. "I know you."

Olivia had seen him on the first Hulk scene in Chicago. Harry Dresden, that was his name. He was a consultant for the Chicago Police Department, Olivia remembered.

"What are you doing here?"

Was he involved with all of this? Working with Clarkson?

"Uh…hi!" Dresden said, looking at everything but her eyes. He'd done that before, talking at people's chins, his eyes always flickering away. It was unsettling. "That's kind of a long story."

"What happened?" Olivia asked.

Before he could reply, a group of civilians passed by, possibly drunk, and a few "Holy crap!" coupled with "My God!" or "What the frak!" comments ensued. The passers-by were quick to bolt, clearly frightened, so Olivia turned her attention back to Dresden and his—where had they gone? They were nowhere in sight.

Again, what the hell happened? Olivia had only looked away for a handful of seconds. How could they be gone?

She looked around, and she was pretty sure it looked frantic but she didn't care. She checked in every direction, and checked again. They really had just _vanished_.

Putting her weapon back to her thigh holster, Olivia let out a sigh. She was starting to feel the fatigue. It was a very strange day, but with her job, burning Hulks and vanishing acts unfortunately weren't anything _that_ surprising anymore.

The smell of burned flesh reminded her of the important questions. Forget how Dresden and his friend had disappeared, it was why that mattered right now. Why were they even here? Were they the ones who had burned the monster? If they were working with Clarkson, why would they eliminate one of their creatures? It didn't make any sense.

Olivia couldn't see how they would have done it either. There weren't any sign of gas on the Hulk, or other inflammatory substances. Spontaneous combustion, then? Was it a new side-effect of the Hulking process?

While thinking over what had happened, she called it in, asking Astrid to send a team to retrieve the body, before moving a dumpster and hiding the burned monster from view. Broyles had said he'd call Chicago PD about Dresden and had asked her to stay vigilant, but Olivia stayed as far away as possible once done, enjoying the night fresh air and keeping away from the nauseous smell.

The first thing that Olivia noticed upon re-entering the main room of the second floor in the office building was that Peter wasn't up on his hawk's nest anymore. She had called him around fifteen minutes ago, while waiting for the team that Astrid had sent to show up. He'd said he was waiting for Agent Rand's team himself, and keeping guard of Clarkson. But it couldn't have been long before the agents had arrived.

An uneasy sensation nagged at her, though, and Olivia found herself jogging her way back. She didn't find Peter. Instead, there were three FBI agents lying unconscious on the ground.

—A—

"How's Agent Rand?" Olivia asked John, one of the EMTs who'd been called in, after Olivia had found Rand's team unconscious.

"He's responsive," John said, "but he'll have to stay in observation for the night. Being knocked unconscious twice in the same evening is serious."

Olivia nodded. The two other agents had been fine too, if stunned. They hadn't been able to tell Olivia what had happened. They didn't know. Someone—or something—had knocked them out, and Dr. Clarkson was gone. Had it been what he'd been waiting for? Did Dresden do this? And how? They had no idea.

"Is it always like this?" John asked, pushing Olivia out of her thoughts. _Was it?_ He must have misinterpreted her look because he said, "I was there last month at the CAT Squad concert."

"Yes," Olivia said, and tried to smile, "I remember."

The Fringe team and a bunch of other people that had been involved in the third Hulk incident had regrouped at Carter's for drinks afterwards. John and his colleague, the two EMTs that had been called on scene, had joined the group, on the invitation of Carina Miller, one of the CAT Squad co-singer.

"It's…yeah, I guess it's pretty much routine."

"I see," John said. "Did you need someone to look at you? Your neck's bruised."

"No, I'm fine," Olivia said, as she brought a hand around said neck. She'd almost forgotten about that. "I need to go back."

He didn't look convinced, but Olivia's phone buzzed and she indicated him to wait so she could take the call.

"Olivia, it's Astrid. Are you still with the medics?"

"Yes. They're getting ready to take Agent Rand's team to the hospital," Olivia said into the phone. "I'm going back inside. What's the situation?"

"Peter and Lincoln are still pinned down by at least two Hulks," Astrid said. "But we think we manage to close the breach for good."

"Good job," Olivia said. She didn't know how they did it, but she'd ask later.

"Walter wanted to talk to you."

"What is it, Walter?"

"Olivia," he said. Just by the way he intoned her first name, she knew he was excited about whatever he had to say. "I think I know how to stop the Hulks. Can you inquire what drugs the medical team has in their possession?"

_Drugs,_ Olivia thought,_ what a surprise._

* * *

**A/N:** _And that's all for today. See you sometime next week for the last chapter. In the meantime, happy holidays!  
_


	5. Party like an Avenger

**A/N:** _Thanks to_ **katichresis**_ for beta reading this chapter._

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**Chapter 5: Party like an Avenger**

"Are you sure about this?" Peter asked.

Olivia glanced at the syringe she had in hand. She'd stopped being sure of anything a bunch of Hulks ago. Even so, she said, "Yeah. It's gonna be fun."

Peter let out a subdued chuckle. "Tell that to Mantis over there," he said, jerking his head to the side, where Agent Francis was sitting down on the floor behind a shelf.

"I'm fine," Francis said, voice even more hoarse than usual. He'd taken a nasty blow from the previous creature they'd fought on the seventh floor. The way he'd been holding his side afterwards, he had probably cracked a rib or two. "You really think it'll work?"

The last Hulk—finally—was across the archive/study room they were currently in. It had been hit by Agent Ballerman, who'd sniped it from the building across the street, but it hadn't been a fatal shot. After that, the creature had built a siege behind a jumble of knocked over tables, chairs, and shelves. Olivia had a feeling the monster was just scared out of its mind.

"I think the last ones weren't trying to kill us," Olivia said. She shifted her weight from one foot to another. The team had been crouched down for the last five minutes, assessing the situation. "You would've been dead otherwise."

Francis grimaced at the thought, but he didn't deny it.

When Olivia had regrouped with the rest of the team, the people responsible had been arrested, and the Hulking process had stopped, but they still had to fight off a few creatures.

"What if it doesn't work?" Lincoln said.

"What if it does?"

Peter looked away at Olivia's words, back at the Hulk's hiding place, before nodding. "Okay. Let's do this."

Olivia left from the right, getting around the shelf to get to the alley along the wall. She made her approach, slowly, as quietly as possible in the gloom of the room. Going from shelf to shelf, she was careful not to needle herself, or it would be over before it started. Used to carry her gun one handed, it wasn't a problem, but on the move so low to the floor, if she had to shoot, the recoil was likely to unbalance her. Thankfully, her wristcuffs covered all but the end of her fingers.

When she made it to her spot, Olivia signaled to Peter that she was ready.

Peter rose to his feet, his weapon at the ready. "Hey, Hulk," he called, and started to walk slowly on the opposite side from Olivia.

She strained her ears, but didn't hear anything.

"Hulk," Peter said again, drawing out the word to tempt the creature.

There was a careful motion behind the heap of furniture. Nothing as bestial as the early Hulks they had faced. It only reinforced Olivia in her belief. She'd made her plan on the assumption that Dr. Clarkson and his associates' manipulations had been partly succeeding. The creatures had gained in intelligence and agility with every new iteration. They weren't just monsters anymore.

Peter pushed on an archive box next to him, making it fall to the floor, and kept walking. Olivia felt herself tense with every step he took. They'd hope the Hulk would rush to him at some point, but it didn't seem like it wanted to, and Peter was lingering dangerously close now.

So close, he barely had time to duck when a chair flew his way. The Hulk jumped over its fort, screaming an even more human-like roar than any of the creatures before it. Olivia didn't dwell on the thought as she watched the Hulk advance on Peter, now turning its back to her. If the Hulk had known where she was, it didn't show, and she didn't waste time coming out of hiding. Peter straightened up on time to try and throw a punch. He cried out when his fist reached the Hulk's face. The monster pushed him violently, forcing Peter to step backwards in order to regain his balance. That had been enough time for Olivia.

From behind, she circled her right arm tightly around the Hulk's neck, and jabbed the syringe at his collar with her other hand, injecting the creature with the drug concoction that Walter had instructed her to prepare earlier.

The Hulk howled. It shook Olivia off its back, as though she was child-sized. Peter slung another fist when she hit the floor, pratfall, and then another. From her peripheral vision, she saw Lincoln and Francis approaching carefully to cover them. And as Olivia thought that the Hulk was going to throw Peter across the room in a way that would make a hawk jealous of his flight, its movements slowed down. The creature's arms stopped in front of it, hanging in the air for the longest of second, before giving out on its side.

"It's working," Peter said, taking a step back.

Olivia scrambled to her feet. She walked sideways, her gun drawn on the Hulk, circling back to Peter's position. They needn't worry. The creature wobbled, and its eyes rolled out in its head, before it just fainted, collapsing on itself with a thump.

"You okay?" Peter asked, shaking his hand in the air.

"Yeah. You?"

He grimaced as he clenched and unclenched his fist several times. "Nothing broken."

Lincoln and Francis joined them next to the unconscious creature. "Do you really think Walter can save him?" Lincoln asked.

"He'll try," Olivia said, and that was enough for her tonight.

—A—

Walter jumped from his seat when Peter and Olivia re-entered the conference room, making his Iron Man costume swoosh. They'd made a stop by the hospital before coming back to the party. Olivia had been right: Agent Francis had cracked a rib. Lincoln's forehead would be sporting a bump for a few days, just like Olivia's neck would be bruised. And Peter's hand was bandaged. But they were okay. Olivia thanked Walter for his concern, reassuring him that she was fine, and left father and son to catch up while she went over to join Astrid and Agent Broyles. She frowned as she saw that they were watching the news on the conference screen.

"Superheroes?" an elderly man said on the video. "In New York? Give me a break!"

"What's this?" Olivia asked.

"Some passers-by seem to have reported seeing superheroes fighting on the streets," Broyles said. "A few journalists have been all over it, but we're covering it up."

"Prank?" Olivia guessed.

Her boss nodded.

"What about the people we arrested?" Olivia asked.

Astrid changed the video feed. It switched to a holding cell. Inside, a man looking identical to Dr. Clarkson was restrained. He wasn't wearing the same Loki costume, and his hair was shorter. Something told Olivia that the twin Peter had mentioned earlier had neither been a she, nor a spy. It'd been his double, from the alternate universe.

"There were three young men," Astrid said, and the pictures appeared in one corner, "who we identified as college students."

"Clarkson's volunteers," Olivia said.

"Yes. And him," Astrid said, with a nod at the prisoner on screen.

"Captain Lee's Division is on its way to extract him," Broyles said.

"Are we sure it's their Dr. Clarkson?"

"We found his show-me."

"Has he said anything, yet?" Olivia asked.

"Not much," Broyles said. "Except that he doesn't know where his double's gone."

Olivia sighted, studying the man. "Any word from Chicago PD?"

"I talked to the detective who works with Dresden," Broyles said.

"Sergeant Murphy?" Olivia asked, remembering the woman they'd deal with in Chicago. The case had been given to one of Chicago PD's department, called Special Investigations. Whatever that meant.

"Yes. She vouched for him, but she couldn't explain his presence, or his friend's. I've opened an investigation. We already found out that the man claims to be a wizard."

"A…" Olivia glanced at Astrid, who shrugged her shoulders. "A wizard?"

"Yes. He's even in the book. He's a PI apparently using magic to solve his cases. I want you to call back Sergeant Murphy tomorrow, find out what this is about, and if he's involved."

Olivia would have found it completely insane. Peter and Walter, science men as they were, probably wouldn't appreciate hearing about wizardry. But Harry Dresden and his friend _had _magically disappeared. It didn't have to be magic, it was likely just how they'd decided to cover things up—though, wizard? That wasn't exactly discreet. Either way, Olivia would have to find out what had been going on.

Agent Valley showed up at the door as Broyles finished, apparently waiting for something. "You can go Agent Farnsworth," Broyles said. "You're all done for the night. You too, Agent Dunham."

Olivia nodded and her boss left, taking his phone in hand as he passed Agent Valley, still waiting at the door.

Astrid glanced her way. "We thought we should celebrate," she said, as though justifying herself.

It made Olivia smile. "You should," she said. "You stopped the whole thing."

Astrid and Agent Valley had been the ones at the origin of the closure of the breach and the ones who stopped the Hulking process. Since on the field, the breach location had been impeded, and agents had been fighting their way up the building, Astrid and Valley had coordinated with the alternate universe to reach the breach from the other side. Captain Lee and Agent Dunham had in fact simply launched gas grenades through the breach, putting to sleep the people who they hadn't known at the time to be Clarkson's double and the rest of the volunteers, therefore stopping their actions.

That was what had stopped the multiplication of Hulks.

Once they had finally made it to the location and arrested the people that had been gassed, the team had finished dealing with the preexisting Hulks, all now dead except for the one Walter's drugs had immobilized.

Astrid smiled at the compliment, before brushing it away.

"What about the man we drugged," Olivia asked, as they walked to the Bishops.

"He had to be put in a coma," Astrid said. "He's been transported to Massive Dynamic."

"I have hope that I can find an antidote," Walter said. "But if I fail to do so, Massive Dynamic might be able to make his life easier."

Olivia inwardly winced at the thought. Massive Dynamic had helped other people with that kind of conditions before—sometimes creating them—but the Hulkian man would be a lab rat for the rest of his days if he couldn't be changed back.

"And we'll start working on it tomorrow," Peter said, grabbing Olivia's hand, "but for now, why don't we go see if there's any birthday cake left, huh?"

"What a fantastic idea, Peter," Walter said. "I'm starving!"

—A—

"Son of Clark!" Nina said, concluding their discussion of tonight's events, and making Peter laughed.

Lincoln looked up, as though someone was calling him. Peter's laugh only grew warmer. Their partner had put on a suit over the top of his rather disheveled Superman costume, and with his glasses back on, he definitely sold the Clark Kent look.

Olivia had wanted to just change, but Peter had insisted, and after showering, she'd put on the leather jumpsuit once again with a fresh t-shirt underneath. Peter had done the same, and contrarily to Olivia who'd gotten rid of her wristcuffs and other gadgets, he wouldn't leave his crossbow anymore. She was beginning to worry he'd sleep next to it.

"I'm gonna go grab a drink," Olivia told the group, excusing herself.

She walked to the bar, and caught sight of a beverage fountain, perplexed.

"Stop the presses! Who is that?" someone said next to her, supposedly trying to be discreet, but failing miserably. "Vicky Vale."

Olivia followed the two men's gaze.

"What?" his buddy said. "No, it's obviously Ms. Marvel."

The woman was indeed wearing a Ms. Marvel costume; she was also Sarah Walker.

"Oh, right. I think it's that Aussie actress from the serial killer show," Olivia last heard of the conversation, but before she could correct them—Come on! Who didn't know the former CAT Squad singer?—Agent Dunham joined her.

"Nice!" the redhead said, serving herself a glass at the fountain. She and Captain Lee had just come back to the party. "Dr. Pepper's the birthday girl's favorite. Want one?"

"Sure," Olivia said. "So we know whose birthday it is?"

"Only rumors," Agent Dunham replied, filling up another glass, "but we missed her too. Bummer to miss the CAT Squad singing earlier."

"They sung?" Olivia said.

"Yeah."

_Freaking Hulks, _Olivia thought. She would have loved to see the trio on stage again.

"I think they announced that they were working together again too," Agent Dunham said.

Olivia only nodded, but judging by the amused look that Agent Dunham gave her, the redhead could tell that Olivia wasn't hiding her excitement over the news very well.

"Someone told me Joseph Gordon-Levitt was there as well. Rumor has it that she didn't want to disturb his current shooting over on our side, big movie or something, so she asked for your Joseph Gordon-Levitt to be there instead."

"Olivia?"

Both agents looked at the person calling their name.

"Hey, Sarah," Agent Dunham said.

"Hi! I thought you guys might be here," Sarah said. "You should come have a drink with us. Did you enjoy the show?"

"We had a bit of a situation, unfortunately," Agent Dunham said. "We missed part of the evening."

"Everything all right?"

"Yeah, we got the bad guys," Agent Dunham said. "Your bad guys actually, you now can rest easy. There won't be any more Hulks running around."

"Well that's a relief," Sarah said. "More reason to celebrate! Actually, Rick and Kate are here as well, we could catch up."

"Sounds like fun," Olivia said.

—A—

"So who was your Loki?" Carina Miller asked.

"Um," Peter said, "that's kind of a long story, but he left."

"Shame, I do a mean Loki," Carina said.

"She does," Zondra Rizzo, her co-singer, agreed. "Loki in a skirt."

Something told Olivia there were more to that story, but she didn't dare ask. She'd found out rapidly that the life of a pop star was rather colorful.

The party was coming to an end now, but after meeting up with Sarah, Carina, and Zondra from the CAT Squad, along with Chuck Bartowski, Sarah's boyfriend, and Richard Castle and Kate Beckett, two of the people they had met on the third Hulk case last month, the team had been having a blast.

Astrid and Agent Valley had volunteered to bring Walter back to their hotel, so Olivia and Peter were now enjoying their night off, even though Olivia felt like she hadn't slept for at least two days.

"What about Scar Man over there?" Olivia heard Carina asked, and she realized she'd zoned out.

"Taken," Peter said. "Clark Kent's single."

Carina seemed to be considering it for a few seconds, studying Lincoln with a frightening intensity.

"Who?" Zondra asked, beside her. She followed Carina's look to where Agent Francis and Lincoln were chatting. "Who did you see?"

"Clark Kent," Carina said. "His buddy's taken."

Zondra's eyes took on a frightening studying intensity of their own. "He's cute."

"He wears the costume well," Carina agreed.

"You're on."

They departed before Olivia could be sure what the two pop stars had actually been discussing. She glanced at Peter, whose eyebrows were up to his hairline.

"Oh, boy," Chuck said.

"They're not that bad," Sarah said. "Mostly."

"At least he's in for a treat, am I right?" Castle said. His laughter sobered at Kate's disapproving look. "Or not."

Chuck shook his head. "No, he definitely is."

"Anyway," Kate said, "what about New Year's Eve?"

"Oh, yes!" Castle said. "Come on, it'll be fun."

Richard Castle, famous writer and all around celeb-New Yorker, was throwing a New Year's Eve party, and had insisted that it would be an honor to have them all. "Sarah and Chuck have already said they'd come," he added when Peter glanced to Olivia. A few lights turned off at the back of the room. "Looks like the party's closing up. How about we discuss this with a drink back at my place?"

"Oh, you have to show me that game we talked about!" Chuck said.

Judging by how Peter's eyes lit up at the mention of the game, he wanted to see it too.

"We're going to have to make sure that everybody gets back home safely," Olivia said. They'd have to escort every remaining guest from the other universe back to The Bridge. "But we're staying in the city for the weekend, so why not?"

"I guess we won't see the birthday girl, after all," Sarah said, when they started to move.

"Yeah," Olivia said. Their host had been nowhere in sight, though they had finally learned her identity. "I just hope this Frea at least knows I don't dress up as Black Widow just for anybody."

**Fin.**

* * *

**A/N:** _Thank you all for reading and letting me know what you thought of the story. Thank you also to_ **JoeltotheD**, **katichresis**, **LinShoe85**_, and _**mxpw**_ for their beta work and support._ _If you're familiar with_ The Dresden Files_, you can follow Dr. Clarkson's adventures in my story: _A Jolly, Rocky, Molly Night_. Either way, I hope you'll have a great time on New Year's Eve. Happy holidays, everyone! See you in 2013. And again:_

_Happy birthday, Frea!_


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